Inglis was actually a separate company at that time - Whirlpool did not manufacture for them. Inglis had it's own manufacturing facilities in Canada.
Whirlpool had purchased a 33% ownership in Inglis in 1969, increasing it to over 50% in 1985, 71% in 1987. Because of this relationship, Inglis built machines based on the Whirlpool designs & platform (prior to the acquistions, Inglis still purchased the designs). In 2001, Inglis Limited was renamed Whirlpool Canada.
Whirlpool USA began badging entry level appliances as Inglis for Best Buy in the US over the past few years as I understand.